Device for heating forging pieces by electric-resistance heating



Dec. 11,1923. I 1,477,009

E. SCHRODER DEVICE. FOR HEATING FORGING PIECES BY ELECTRIC RESISTANCE HEATING Filed July 6. 1921 Patented Dec. 11, 1923.

UNITED STATES I 1,477,009 PATENT OFFICE.

EDMUND SCHRGDER, OF BERLIN, GERMANY, ASSIGNOR TO THE FIRM BRAUN-BR'U- NING & 00., OF BASEL, SWITZERLAND.

DEVICE FOR HEATING FOR-GING PIECES BY ELECTRIC-RESISTANCE HEATING,

Application filed July 6,

To all whom it may concern:

Be it known that I, EDMUND SoHRiiDER, engineer, citizen of the German Republic, and residing at Nos. 48-51 Maybach-Ufer, Berlin, Germany, have invented certain new and useful Improvements in Devices for Heating Forging Pieces by Electri.cResistance Heating, of which the following is a specification.

This invention relates to a device for heating forging pieces by an electric current. This device excels the known devices of similar kind by its capability of adaptation to the given circumstances, as well as by its constructional strength whereby it is made very resistible to wear and tear.

The invention is illustrated in the acco1npanying drawing in which Figure 1 is a perspective view of the device. Figure 2 is a vertical section through the chief parts; and Figures 3 and 4 are details which are also duly described in detail hereinafter.

a b and a b are two pairs of grip-ping jaws, of which a is in contact with a copper or brass or bronze tube 0 and a is in contact with a like tube 03. The two tubes are connected at e and f with the secondary poles of a transformer 9 located in an oil box it which in its turn is located in a water vessel 2'.

The jaws a a have each at the rear a semicircular groove corresponding to the tubes 0 and d, and besides said grooves semicircular recesses are provided receiving each a ring j (Fig. 3) which encompasses the respective tube (0 or d) and is made integral with a threaded spindle j which passes through the associate jaw (I) or b) and carries in front of this latter a hand wheel y. The jaws a and a consist preferably of copper.

As long as the jaws b and b are not pressed against the jaws a and a by means of the hand wheels 9' and the spindles j, they may be easily displaced along the tubes 0 and 65. Only when the work piece has been clamped fast in the jaw pairs whereby the rear half of each ring j is drawn tight against the respective tube (0 and d), the jaws a and a are firmly pressed against said tubes so that a very good contact is established. 1

Owing to the jaws being not only displaceable along the tubes 0 and d in horizontal direction, but also rotatable upon them in vertical direction, they are excel- 1921. Serial No. 482,740.

lently adjustable and fit for adaptation to any requirement.

Straight pieces which are to be heated between their ends, or for any portion between the latter respectively, are clamped in between the jaws after these have been suitably displaced in horizontal direction upon the tubes 0 and d. The circuit is then closed by the stepped switch t, Figure 1, and the voltage is appropriately adjusted. If curved pieces are to be heated, either one of the jaw pairs is, or both jaw pairs are, moved not only horizontally, but also vertically, just as the configuration of the respective piece requires. If it is a circular piece, for instance a wheel rim or the like, as in Figure 4, the spindles j are turned upwards into vertical position and the wheel rim etc is clamped in horizontal position, as shown. If a work piece is to be heated at one end only, it is, firstly, clamped between the jaws a and b in such a manner that the end to be heated extends in the direction to the other jaws (a and 6). Then a metal block forming an auxiliary electrode is clamped in between the jaws a and b and these latter together with said block are shoved against the work piece, that is to say, against the end to be heated.

The tube 0 has cover-like end-pieces c c by means of which it is afiixed to a horizontal rod 02 (Fig. 2) supported at its lefthand end in a vertically bent-off arm of a horizontal carrier m and extending in the other direction through a pipe d connected with cover-like end-pieces 6Z2 6Z3 of the tube d. as well as with the other bent-off arm of said carrier m. The pipe d is secured in said latter arm by the neighbouring end-piece (Z and a collar d attached to the projecting end of the pipe d. The righthand end of the rod n is threaded and carries a handwheel 30, and a spring 1? is arranged between this hand wheel and the collar (1*. The tube 0 and the respective transformer pole are movably connected with each other by the mediation of a flexible member 14 which is connected at one end with that pole and at the other end with the end-disk 0 The other pole is rigidly connected with the end-disk d 7* is a U-shaped tube which is hinged at its ends to the frame of the machine and forms a treadle which is connected at one side with a rope 7 T the other end of which is attached to a lever-like twin nieinber (Fig, 1) which is hinged to the projecting end of the rod mV (at the lefthand end oi? it) and forms at its centre parts two cainswhich draw the rod n to the left when the 'treadle r is depressed.

If a work-piece is to be heated through its entire length, it is clamped in either between auxiliary blocks inserted between the jaws a Z) and a b, or between the lateral surfaces of these jaws themselves but prior thereto the jaws a and b have been so adjusted upon the tubes oaiid (Z that to secure the workpiece linelly in its place only the treadle 7" need be depressed and then let loose so as first to increase the space between the tubes 0 and d by the means described and then decrease it when the lateral sur faces oi? the jaws will grip the piece and hold it. fast.

Each of the jaws may have one or more holes to reccireauxiliary electrodes of any desired or suitable shape, by the mediation of which the \VOlli-PIOCO may be heated just in. the portion or zone required for the purpose. Owing to the possibility of moving the tube 0 in the direction to the tube (Z by means of the hand-wheel y), the apparatus may be employed for jinnping or jogging, and it may be einployed'also as butt-welding machine.

The tubes 0 and (i may be connected with a water-conduit for conducting cooling;- Wt-l iifll through them during the welding 0poration.

Having now described. my invention, what I desire to secure by a patent 01"" the United States is:

1. A device tlor l'i-eaiting forging pieces and the like l'iy electrical resistance heating, comprising, in combination, two co aiiial tubes; a tin-nsforiner; conducting connect-ions between said tubes and the poles of said transformer; and two pairs oi? gripping jaws, oi which one is in Contact with one of said tubes and the otheris in contact with the otier of said tubes; said pairs of jai eing adapted to be displaced along the said tubes, as well as to be turnedupon them, for the purpose set forth.

2. A device for heating forging pieces and the like by electric 1' istunce heating, comprising, in combination: two coaxial. tubes, of which the one is adapted to be displaced in the direction to the other; a treadle; a, connection between. said displrtceable tube and. hid treadle; elastic means for automatically moving the said tube back into its former positions trans'iornie-r; condr ting" connections-i between said tubes and the poles (it said transformer; and two ntirs 0i ij'ipiiig jaws, oi which one is in contact with one oi said tubes and the other is in contact with the other of said tubes; said pairs of jaws being adapted to be displaced along the said tubes as well as to be turned upon them for the purpose set forth.

In. witness whereof I have hereunto set my han d.

EDMUND SCHRQDEB. 

